CA2263438A1 - Pump protection fitting - Google Patents

Abstract

The invention relates to a pump protection fitting, comprising a housing (1) with a pump connection piece (2) arranged in the main direction of flow (R), a feed water connection piece (3) opposite thereto, a bypass connection piece (4) arranged perpendicular to the main direction of flow (R) and a closure (5) for an assembly plate located opposite the bypass connection piece (4). A nonreturn valve plate (7) is movably arranged between the closure (5) and the bypass connection piece (4) with a valve spindle (6) and which is optionally spring-loaded in relation to a valve seat (8) located opposite the assembly plate closure (5). The non-return valve plate (7) actuates an at least onestep throttle valve (9) which is coaxial thereto and which is completely opened when the non-return valve plate (7) is closed and produces a bypass (10) from the pump connection to the bypass connection piece (4). The valve spindle (6) has one or several throttle bodies (11). The end (lower side) of said valve spindle is allocated a security stop (SA) which is arranged in the bypass connection piece to limit waste. The self-controlled valve spindle (6) is moved in the same direction by a gear-like lifting mechanism (H) and is coaxially arranged in the housing (1) of the three-way straightway valve.

Description

Pump-Protecting Armature The invent~ion relates to a pump-protecting armature having an armature hou6ing, further having a punp connecting branch dispo~ed in a primary ~low direction, a feed-water connecting branch opposite rhe pump ~onnecting branch, as well as a bypas~s branch di~posed rrans~er~ely to the prirrLary ~low direction and a mounting-pl~ate cap oppo~ite the bypass branch, betwee~n which a chock-valve disk is seated, possibly spring-ln~e~, on a valve spindl~ :
so as to be di-~placed with re~pect to a valv~ ~eat oppo~lta the mounting-plate cap, with the chec~-valve diQk actuating an a~ lea~t single--~tage throttle va~ve coaxial ~o the val~e disk, the valve being:-completely open when the check-valve disk is closed and producing a ~ypas3 from t~e pump-connection ~ide to the bypass branch.
High pre6sure6 can occur in 6uch pump-pro~ecting armat~re~ or valve~, which are known in variow :embodiments, for example from D~3 g4 22 7~9 C2; a disadvantage o~thi~ is that, becau6e o~ the ~eating of the ~alve spindle with~throttling bodies in the armature housing, the valve spindle~ can break of~ or loosen from their seat (holding device) and fall down in the armature housing, causing~alfunctjo~;n~. ~
DiQposed a~ the valve pindle i~ one or a plurality of coaxial throttling bodies ~erving ln ~hrote,ling the pre~3ure on ~he inflow side when the control armature~is closed and the thro~tling valve (bypass ~alve~ is open.

The disadvantage of ~his arrangemen~ is tha~ the thro~tling bodie~ cannot have an arbitrarily-large size, because the orces effec~ed by the val~e ~pindl~ would reach an unacceptable magnitude Furthermore, ~t i8 disadvantageous that, when the pump is ~witched of$, the medium can flow back out of the bypass branch disposed on the di~charge 6ide a~ the ~hrottle val~e.
It ls ehe object of the inven~ion to improve a pump-protecting armature ha~ing the design mentione~ at the outset such tha~ the valve ~pindle ha~i~g throttling bodie~ i~ secured in its poaition in a simple and cost-effective ~n r, which increaseE the reliability and safety of the armature and a~oids malfunctioni~g.
In accordance with the invention, this ob~ect is accompli~hed in that a safety stop for limi~ing ~alls;
which iq dispo~ed in:the bypa6s ~ranch, i~ assQciated with the end side (lower end) of the val~e 3pindle having one ar more throttling bodiee.
The derend~nt claims disnlose design fea~ures that represent ad~antageou~ and beneficial modifica~lon~ of the ~ol~ion, in different variations.
A ~ignificant~advantage attained with th~ ~afety stop of the inven~ion, which is aQsociated with th- end side of valve spindle having throttling bodie~, is tha~ the valve ~pindle cannot fall into ~he bypa~s branch after loo~; ng from its holding de~ice or being damaged, bre-king o~ or the like, but the discance i~ can fall is limited, and i~
. - 2 iB caught by the s~op, which precludes malfunct~.oning, and the throet}ing bodies continue ~o be held with ~
sufficien~ flow-through ~pacing from the throttle tage~.
Thi6 safety stop i~ formed:from simple co~conent~, and can be embodled in the form of constriction~ in the control bl~hin~ of the bypas~ valve, through th~ insertion of perforated di k or perforated baskets into the control bll.ch~ n~ or in~o a separate, ~econd control bushing:, by di3ks, etc., and is alwayQ fipaced beneath the la t throttling-body s~age. ~Pin~ and piston~part~ ~f the valve ~apindle can also cooperate with the safety StO~.
With respect to the valve spindlo~and~the throttling stages, the diameter of the thro~tling bodie~ elected such that the recoil ~orces on the main valve body ca~ be kept mall. ~The throttling ~odies should not ha~e an exceesively-large diameter so ae ~o l~mit the recoil o~ce~ on the check-valve di~k, : -a) for keeping material stre~e6 at ehe val~e spindle : f~rom bec~ g exce~sive in th- smalle t Cro~s ~ ection, and~
b) ~or keeping the pressure loss in the :main ~low as-small a~ posslble.
On the other hand, ho~ever, the recoil fcrce~ must belarge enough to as~ure a proper re~toration o~ the check-val~e disk.
A further advantage~is the use of a le~e~ mec~n;.sm in connection with the throttling bodies and ehe bypa~s :

valve as a building block that permlts easy:as~embly and has a positive influence on the safety o~ the armature function.
A further advantage i3 the friction dalnpi ~ , which i~
formed by a mecha~ical, s-lf-ad]u3ting friction-damping element or a hydraulic friction damper surrolln~ the val~e ~pindle above the~check-valve disk, and acting on the disk. ~
Another advantage i3 the ~ hoA~lnent of th- throttle valve (~ypass ~alve) wlth a piseon mounted to the valve epindle, whLch pi ton extend3 into a control~bushing acting a~ a safety stop, wi~h the e~fec~ of a pi ton valve or a partially-re}ieved bypass valve re~ulting from the cros6-section ratios between the piston and the control bu-~hing and a bore ext~n~ing in the ~alve 6pi~dle.
The drawings illu~trate variatione of an ~mbodiment of the invention, which~will be explalned in detail below.
9hown are~ in:
Fig.~l a longitll~in~l sec~ion thro~gh ~ pump~- , protecting armature having a hou~ing with a pump~connecting branch, a feed-water connec~ing bra~ch opposite the pump connecting branch, a che~ck-val~e disk cooperating with a ~alve ~eat, a bypa s branch having a thro~tle valve-and oriented transver~ely to the branches, ~nd a single-stage throt~ling body dispo~ed at a valve , .
_ , .

splndle and a safety ~top formed by a con~triction in the throttle val~e for the val~e spindle having a ~hrottlin~ body;
Fig. 2 a longitudinal ~ection through the pump-procecting arma~ure having a sa~ety stop ~ formed by a perforated di6k;
Fig. 3 ~ a longitl~;n~l section through ~he pump-protecting armature having a safe~y stop f~rmed by a disk;
Fig. 4 a longit~ldi~l section through the pump-protecting armature ha~ing a sa2ety ~top ~ormed by a perforated dls~, with which a spring-loaded clo ing diQk is a~sociated;
Fig. 5 a 1onglt~i n~l s~ction through the pump-pro~ecting armature having multl-stage -throttling bodies and a perforated di~k a~
a 6afety top;
Fig. 6 a longit~l~;nAl ~ection through the pump-protecting aXmature having a sa~ety 2top - formed by a perforated ba~ket that has guide and support pins;
Fig. 7 a longitll~i~a~ Bection through the pump-proteccing armature ha~ing a sa~ety stop formed by a perforated ~asket and cooperating with a pin tha~ iB exrended at the lowermo6t ~hrottling ~ody, the armature ~urther having a spring-loaded, ~eparate .~

throttling body and an addi~ional perforated disk;
Flg. a :a longit~in~l 6ection through the pump-protecting armature corre p~n~ tO Flg.
7, but without a perforated disk;
Fig. 9 a section through the pump-prot~_ting armaturc having a~safety stop formed with a perforated di~k and a spring-loaded valve ~pindle~having thro~tling bodie~ tha~ i~
~supported on th~ per~ora~ed di6~;
Fig. lo a longitudinal sec~ion through the p~mp-protecting armature having a safety ~~op formed by a perforated basket and additiona~ throt~ling bodie~ thae are displaceable, with s~ring loading, on a guide and support pin of:the valve ~pindle;
Fig. 11 a longitudinal Ecction through the pump-prorecting armature ha~ing a perforated basket ~a~ a sa~ety ~top and a compres~ion pring di6posed between the perforated bask-t and the throttling body;
Fig. lla an enlarged 6e~ion from Fig. 11;
- Fig.-12 a longitudinal section through ~he p~mp- ~
protecting armature having a second control bl~hing, which forms ~he ~a~ety s~op and a piston of the valve 6pindle tha~ ext4nds into the bushing;

.

Fig. 12a an enlarged section from Fig. 12;
Fig. 13 a lo~gitudinal 6ection through the p~p-pro~ecting armature having a second c~ntrol bushing a3 a ~afe~y ~top and a ~prin~-loaded pi3ton of the val~e spindle, and a -~elf-adjusting fric~ion ~m~er surroundln~ ~he val~e spindle and acting on the valve disk;
Fig. 13a an enlarged section:from Fig. 13;
Fig. 14 a longitl~i n~ 1 ~ection ~hrough ~he pump-proteceing armature having hydraulic damping;
and Pig~ 14a an enlarged section from Fig. 14.
The armature hou~ing ~1) of a pump-protec~ing:
armature ha~ a pump connecting branch (2) disposed in a main flow direction (R), a ~eed-water connectiAg branch (3) di~posed opposite the pump conne~ting bran~h, a bypass branch (4) dispo~ed~transv-r~ely tc the ~ain f~ow~ :
dlrec~ion (R) and a moun~ing-plat- Cdp ~housir~ lid) (s) opposite the bypass branch ~4). Between the m~unting-plate cap (5j and the:bypa~s branch ~4), a check-valve disk (7) i~ ea~ed, possibly spring-loaded, to be di~placed~with a ~alve 6pindle (6) with re~pect to a val~e seat (8) opposite the mount~ing-plate cap (5). The check-valve disk (7) io coupled to a throttle valve ~!9) that is coaxidl to the diSk and has at least one stag~. ~he valve being completely open when the check-valve di~k ~7) is closed, and prdduclng d byPa~ (10) ~rom th~ pun~p-connection side (2) to the bypass branch (2) ~ic]. A
safety stop (SA) for limiting falls, which is disposed in ~he bypa~6 branch ~4), i~ associated wleh the ond side (lower end) of ~he valve spi~dle (6) having ono or more throttling bodies.

The throt~le valve (9) has a control bushing (12) that i~ secured in the bypass branch (4), the ~.q~l n~
forming single- or multi-stage cascades (~) wlth the throttle body (bodies) (11) loca~d therein. -~he safety 9top (SA) according to Fig. l is formed by a ccnstriction ~13) of the control bushing (12) secured, pref~rably screwed, in the bypass branch (4), the con~triction ha~ing a smaller dia~meter than the throttling body (11); in the region of the constriction (13), the control h~ n~ (12) has on the inside flow-through chAnn~ 14) t~at extend in the ~ypa~-flow dlreccion, and permit a byp~s~ flow for avoiding mal~unctioning in the armature when the valve spindle ~6)~ha ~allen with a throttling body ~ll) di posed i~ the constriction (13).

The cafety stop ~SA) accordlng to Fig. 2 ~9 formed by a perforated di~k (15) ~ecured in the bypass branch (4), beneath the control bll~h~; n~ (12).
In accordance wlth Fig. 3, a second, do.~ d-projecting ~control b~sh;n~ (16) is inserted, preferably scre~ed, into the control bu3hing (12), with a disk (17) being:ln~erted, with a sealing e~ ect, a~ a saSety stop (SA) i~to the second control bushing. The valve Qpindle ~ 8 - :

:

(6) ha~ two throttling bodies (11) and, at i~s lower end, a piston (18) having axial flow-~hroug~ ch~nnPls (19) ~ the pi~ton being fornted onto the val~e spindle ~6) ~s a further throttling body. The second con~rol bushing (16) has on it8 jacket side flow-through openings (~0), which are closed by the pisto~ (18) when the throttle ~alve (9) i~ closed.
In accordance with Fig. 4, ~ the safety st~o~ (SA) is formed b~ a per~orated disk (22) that rest~ against the lower end f ace of the control bus~,ting ( 12 ) and i6 held in a shoulder (21) of the bypa~ branch ~4)S bene~h the perfora~:ed :di6k (22) is ~a closing di3k (23) th~c i8 axially~movable with re pect ~o the perforated disk into th- position that enables and blockq ~he flow-through by meanq of a cap bolt:(24) that i:s ~ecured, pref~rably riveted,~to the pcrforated disk (2~), and by mean~ of a compression ~pring (25) ~urrounding ~he cap bo~t. The ~valve spindle (6) has three thrott:ling bodle ~11) that are spaced axially one h~ the other, and ef~ect three-stage cascada6 ~K).
-The cascade~ (K) are formed by annular constriccions (26) of the control btl.sh~ (12), which are ad~pted in -diameter to the throttling bodie ~ll) and for~ the valve ~eat for the throttling body (11). One thro~t~ing ~ody (11), ~pecifically the lo~ermost or uppermo~t throttling body ~ll), cooperateg with a valYe seat ~26) in the clo~ed position; the other throt~ling bodies (ll) have no closing _ g _ .

~ CA 02263438 1999-02-10 function, but lie with a loo~e fit in the control bushing ~12).
In the further embodiment according to ~iq. S, a per~orated disk ~2'~ inserted aB a safety stop (SA~
into the control b~sh~ l12~ and held thereln ~y a retaining ring (2fi). The end-side throttling body (11) has an axial pin (29), which is surrounded by a co~pression spring (30) ~upported on the perfor~ted disk : (27) and against the throt~ling body ~11).
In accordance with Fig. 6, a cup-shaped, per~ora~ed ba~ket (32) ha~ing on its jacket and botrom si~es flow-through openings (31) i-~ ~ecured to the lower ~nd of the control bushing (12); this basket support~ a c~tral guide and support pin ~33~,: which ~orms the safety s~p (SA), around which the two 3uperposed, spaced, separ~te throttling bodies ~35), which are re~pectively ~cted on by a compression pring (34~, and:reqpective1y have a valve eeat ~35a), are seated so as to be di placed ir.to a c10sed and an open position.
A cup-shaped, perforated ba~ket~(32) havir.g flow-through oren1n~s ~31~ on its jacket and bottom ~ides i~
1ikewise secur~d as a sa ety ~top (SA) at the ~ower end of the control b~ n~ (12) according tO Flg. 8, ~nd the lowermo~t throttli~g body (11) has an axial, downward-ext~Ai-l~ pin (36) provided with~ a~ collar (37) that is screwed onto the ide of the free end; seated ~round the pin ~36~ ~o as ~o ~e axially dispIaced in~o an open and a - 1 0 - ~ :

closed posicion is a 6eparate throttling body ~3S) that i~
acted on by a co~pre~s~ion spring (34) and has a valve seat (35a).
A perforated disk (38) can additionally be secured with ~pacing beneath the perforated bot:tom (32a) of the~
perforated ba.~ket (32) ~(Fig. 7).
The e~boAlment according to Fig. lO corr~ o~d.~ to the embodiment according to Fig-. 8, but the ~eparate throttling body (35) ha~ cwo val~e seats 135a) -~isposed one hek;~d the other in the axial direction.
In accordance with Fig.:9, a perforated di6k (27) is in~ertcd a-~ a ~afety stop (SA~ into the contro~ bu~h;
(12) and held therein by a retA~in~ ring (~B); the lowermo~t throttling body (ll) :has a formed-on, axial hollow pin (39), ineo which~a cG,-.~easion pri~g (40) ~uppor~ed o~ the p-rforated disk (27) extend6.
In accordance with Figs. 1l and lla, a cu~-6haped, perforated basket (41) having flow-through ope~ings (31) on it8 j acket and bottom sides i~ ~ecured as a 6afe~y stop ~(S~) benoath and at the control bllQhin~ ~l2)~ ~referably screwed with a~sealing ef~ect onto the control b~h~
(12); between the cup botto~ ~3~2a) o~ the perforated:
basket :(32) and the:lowermost throttling body ll~ i~ a compre~sion spring ~40) that i~ ~upported on the cup ~octom ~32a) and in a-hole (~l) of the ~hrottll.ng body (11) . -In ehe further ~aria~ion according to Fig-. 12 and ' : ' ' 12a, a second cup-shaped control b~q~n~ (42) 12~ving flow-through openings (42a) on i~s jacket side iQ ~-cured ae a eafety stop (SA) at the control bushing (12); a piston (43) formed onto the lowermoet throttling body (ll), ~ith the int~rpo3ing of a compreesion spring ~40), ~xtends into this control bushing ~o as ~o be axially di~pla ed, with a ~ealing effect, with~reapect to the oecond con~rol bushing (42~.
~ igs. 13 and 13a 6~0w a socond cup-ehaped control bushing (42) that hae:~lo~-through or~ s ~42a) on ite jacket ~ide and i~ ~crewed, with a 6ealing effect, onto the first concrol buehing (12).
The valve ~pindle (6) displaceably extend~ ineo the - second control- bllQhln~ (42) with a piston ~4~) that i~
secured to a valve-~pindle pin ~44a) with spac~ng from ~he lowermost throttling body (11), with ehe 1~terposing o~ a compression spring (4 o ) ~ ~
In rhe valve-spindle pin (44a), an axial ch~nn l (54) extendg ~rom the lower, free pin end face proj-cting beyond the piston (44), from which ch~nnel an ~xit bore (54a) ~hat i~ emaller in diameter extends~laterally from above the piston (44).
The further e~oA;~nt according to Figs. 14 and 14a :corresponds to t~e ~ho~ment aocording to ~ig~. 11 and lla, with a second cup-shaped control bushing ~32) that ha~ flow-through apenings (313 on it jacket a.qd bottom ~sides likewis~ being ~ecured to the control bUi-hin~ (12) - ' . _ addicionally, a perforatcd dlsk ~38) i~ in6ert~d as a ~afe~y stop ~SA) into thi6 control bushing, with 3pacing above the cup bottom (32a), and a compression ~pring ~40) supported on the perforated di~k (38) a~d in a blind bore (gl) of the throttling body (ll) i9 disposed b~tween the perforated di~k (381 and the lower ehrottling ~ody lll).
At the moun~ing-plate cap (5~, a pivotally-seated lever mechanism ~H) is coupled to the throttle val~e (9j via ~he check-valve di~k (7) ! and the lever meehani~m (H) and the throttle ~alve (9) are connec~ed to form a unit.
Surroll~A~n~ the valve ~pindle (6) i~ a self-adjusting friction damper (~D), which coopera~es with th~ check-val~re diek ~7) and coTnprise~ a cup housing (45 3 detachably ee~cured to th~ check-valve di~k t7) by meane o~ a flange joint (48) and~plastlc ~unk ring~ (47), which are disposed in the hou~ing ln a roo~ shape~an~ are held wir,h prestressing oppo6ite t~e check-valve di3k (~ with the interposing of a compree ion spr1ng (46) (Figs 11, lla, 12, 12a,; 13, 13a).
Fig~. 14 and 14a show a hydraulic damper ;HDi ~
comprising a pistQn ~50~) t~at is provided at~ the control bushing (12), i~ seated around the valve spind~e (6), extends lnto a valve bore ~49a) o~ the check-~alve di~k (7) ~o aR to be axially di~placeable, with a 3ealing effect, and i~ self-deventilating.
In ~e ~ho~;ment~according~to Pigs. 12 and 12a, the aelf-adjusting, spring-loaded friction damper (RD) formed . ., from junk rings:(47) is a3sociated with the ch-~k-val~e disk t7), and the pi~ton (43) o~ the throttlin~-body ~alve spindle (6) that extend~ into the second control bushing 142) scre~ed on~o the control b~ h;~g (12~, an~ is under 6pring ten6ion (~0), i~ associated with the thr3ttle val~e (9) as a hydraulic damper (HD); exten~jn~ in ~h piston (43) and in the throttling bodies (ll) is a lo~g connecting chA~nel (51), which lead~ from tho c~nrrol bl-~hi n~ (42) and exi~s the control bu~hing (12) by way of a bore (52) that ha~ a smaller cros~ section, ~ith identical preçsure raeios pre~o~ln~tlng in the ~pace (53) between the piston (4~) and the control bl~Ahlng (42), and in the connecting ~h~nnel ~51, 52), the objective being to keep the recoil force ~mall. :
The d~rer (HD) effects par~ially-relieved ca cade~
(K), and the:difference between the largest width o~ the throttling body (11~) and the lower end face of the piston (43) results in~a partia~l relief of the entire ~hrottle valve/bypa~ valve (9).: :
In accorda~ce with Fig~. 12, 12a, the fric~ion damper (RD) i~ scY~ d ineo the valve disk (7).
The self-adju~tlng friction ~Am~er ~RD) ~ serves in preventing vibrationq of the check-valvè di~k l7).
The spring (46) holds the plastic ~unk ring~ (~7) under stre~ss, and automati~ally adjusts the- fr~cti~n damping a~ wear occur .
In the e~bodiment accordlng to Fig~. 13 ar~d 13a, che : - 14 -last stage ~throttling bQdy ~1 with piston 44) ~perate as a piston ~alve, with the rellef being effected ~ia ~he ch~n~el (54)~extending wi~h the bore (54a) in the valve-6pindle~pin (44aj, thus effecting an additiona- hydraulic damper.
In the ~hoAiment according eo Figs. 3 and 13, the stop disk~ ) and the piston (18), and the bottom of the perforated basket (42~ and the pi n (44~, re~pectively, form a pre ure-relieved piston valve; here th~ piston (18, 44) ~an have an arbitrary diameter without addi~ional force being exer~ed on the lever ~e~nlQm ~H), and thus on the throt~ling body (11~. The~perforated dl~ks (15, 22, 27,:38~ and the per~rated baske~s (32, 42~ likewise ~orm throttling ch~nnPls for the~bypas~.

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' ~ :

'

Claims (21)

1. A pump-protecting armature-having an armature housing, a pump connecting branch disposed in a primary flow direction, a feed-water connecting branch opposite the pump connecting branch, as well as a bypass branch disposed transversely to the primary flow direction and a mounting-plate cap opposite the bypass branch, between which a check-valve disk is seated, possibly spring-loaded, so as to be displaced with a valve spindle with respect to a valve seat opposite the mounting-plate cap, with the check-valve disk actuating an at least single-stage throttle valve coaxial to the valve disk, the valve being completely open when the check-valve disk is closed and producing a bypass from the pump-connection side to the bypass branch, characterized in that a safety stop (SA), which catches a loosened or broken-off valve spindle (6) and is disposed in the bypass branch (4), is associated with the end side (lower end) of the valve spindle (6) having one or more throttling bodies (11).

2. The pump-protecting armature according to claim 1, characterized in that the throttle valve (9) has a control bushing (12) that is secured in the bypass branch (4), the bushing forming single- or multi-stage cascades (K) with the throttling body (bodies) (11) disposed in the bushing.

3. The pump-protecting armature according to claim 1 or 2, characterized in that the safety stop (SA) is formed by a constriction (13) of the control bushing (12) secured, preferably screwed, in the bypass branch (4), the construction shaping a smaller diameter than the throttling body (11), with the control bushing (12) having on the inside flow-through channels (14) that extend in the bypass-flow direction (Fig. 1).

4. The pump-protecting armature according to claim 1 or 2, characterized in that the safety stop (SA) is formed by a perforated disk (15) that is secured in the bypass branch (4), beneath the control bushing (12) (Fig.
2).

5. The pump-protecting armature according to claim 1 or 2, characterized in that a second, downward-projecting control bushing (16) is inserted into the control bushing (12), preferably screwed in, with a disk (17) being inserted, with a sealing effect, as a safety stop (SA) into the second control bushing; at the lower end of the valve spindle (6), a piston (18) having axial flow-through channels (19) is formed onto the valve spindle (6); and the second control bushing (16) has on its jacket side flow-through openings (20), which are closed by the piston (18) when the throttle valve (9) is closed (Fig. 3).

6. The pump-protecting armature according to claim 1 or 2, characterized in that the safety stop (SA) is formed by a perforated disk (22) that rests against the lower end face of the control bushing (12) and is held in a shoulder (21) of the bypass branch (4); beneath the perforated disk is a closing disk (23) that is axially movable with respect to the perforated disk (22) into the position that enables and blocks the flow-through by means of a cap bolt (24) that is secured, preferably riveted, to the perforated disk (22), and by means of a compression spring (25) surrounding the cap bolt (Fig. 4)

7. The pump-protecting armature according to one of claims 1 or 2, characterized in that a perforated disk (27) is inserted as a safety top (SA) into the control bushing (12), and the end-side throttling body (11) has a pin (29), which is surrounded by a compression spring (30) supported on the perforated disk (27) and against the throttling body (11) (Fig. 5).

8. The pulp-protecting armature according to claim 1 or 2, characterized in that a cup-shaped, perforated basket (32) having flow-through openings (31) on its jacket and bottom sides is secured to the lower end of the control bushing (12), the basket supporting a central guide and support pin (33), which forms the safety top (SA), around which two superposed, spaced, separate throttling bodies (35), which are respectively acted on by a compression spring (34), and respectively have a valve seat (35a), are seated so as to be displaced into closed and an open position (Fig. 6).

9. The pump-protecting armature according to claim 1 or 2, characterized in that a cup-shaped, perforated basket (32) having flow-through openings (31) on its jacket and bottom sides is secured as a safety stop (SA) at the lower end of the control bushing (12); and the lowermost throttling body (11) has an axial, downward-extending pin (36) provided with a collar (37) that is screwed onto the side of the free end, and sealed around the pin (36) so as to be axially displaced into an open and a closed position is a separate throttling body (35) that is acted on by a compression spring (34) and has a valve seat (35a) (Figs. 7 and 8).

10. The pump-protecting armature according to claim 9, characterized in that a perforated disk (38) is secured in the bypass branch (4), with spacing beneath the perforated bottom (32a) of the perforated bushing (32) (Fig. 7).

11. The pump-protecting armature according to claim 9, characterized in that the separate throttling body (35) has two valve seats (35a), which are disposed one behind the other in the axial direction (Fig. 10).

12. The pump-protecting armature according to claim 1 or 2, characterized in that a perforated disk (27) is inserted as a safety stop (SA) into the control bushing (12), and the lowermost throttling body (11) has a formed-on, axial hollow pin (39), into which a compression spring (40) supported on the perforated disk (27) extends (Fig.
9).

13. The pump-protecting armature according to claim 1 or 2, characterized in that a second cup-shaped control bushing (32) that has flow-through openings (31 on its jacket and bottom sides is secured to the control bushing (12); and a compression spring (40) supported on the cup bottom (32a) and in a blind bore (41) of the throttling body (11) is disposed between the cup bottom (32a) of the perforated basket (32) and the lowermost throttling body (11) (Figs. 11 and 11a).

14. The pump-protecting armature according to claim 1 or 2, characterized in that a second cup-shaped control bushing (42) having flow-through openings (42a) on its jacket side is secured as a safety stop (SA) at the control bushing (12), and a piston (43) formed onto the lowermost throttling body (11), with the interposing of a compression spring (40), extends into this control bushing so as to be axially displaced, with a sealing effect, with respect to the second control bushing (42) (Fig-. 12 and 12a).

15. The pump-protecting armature according to claim 1 or 2, characterized in that a second cup-shaped control bushing (42) that has flow-through openings (42) on its jacket side is secured at the control bushing (12), and the valve spindle (6) displaceably extends into the second control bushing (42) with a piston (44) that is secured to a valve-spindle pin (44a), with spacing from the lowermost throttling body (11), with the interposing of a compression spring (40) (Figs. 13 and 13a).

16. The pump-protecting armature according to claim 1 or 2, characterized in that a second cup-shaped control bushing (32) that has flow-through openings (31) on its jacket and bottom sides is secured to the control bushing (12); a perforated disk (38) is inserted as a safety stop (SA) into this control bushing, with spacing above the cup bottom (32a); and a compression spring (40) supported on the perforated disk (38) and in a blind bore (41) of the throttling body (11) is disposed between the perforated disk (38) and the lower throttling body (11) (Figs. 14 and 14a).

17. The pump-protecting armature according to one of claims 1 through 16, characterized in that, at the mounting-plate cap (5), a pivotally-seated lever mechanism (H) is coupled to the throttle valve (9) via the check-valve disk (7), and the lever mechanism (H) and the throttle valve (9) are connected to form a unit

18. The pump-protecting armature according to one of claims 1 through 17, characterized in that the valve spindle (6) is disposed to move in the same direction by the gear-shaped lever mechanism (H), and controlled by its own medium and coaxially in the armature housing (1) of the three-way valve.

19. The pump-protecting armature according to one of claims 1 through 18, characterized by a self-adjusting friction damper (RD) that surrounds the valve spindle (6) and cooperates with the check-valve disk (7), and comprises a cup housing (45) that is secured to the check-valve disk (7), and plastic junk rings (47), which are disposed in the housing in roof shape and are held with prestressing opposite the check-valve disk (7), with the interposing of a compression spring (46) (Figs. 1, 11a, 12, 12a, 13, 13a).

20. The pump-protecting armature according to one of claims 1 through 19, characterized by a hydraulic damper (HD) comprising a piston (50) that is provided at the control bushing 12, is seated around the valve spindle (6), extends into a valve bore (49) of the check-valve disk (7) so as to be tightly axially displaceable, and is self-deventilating - Figs. 14 and 14a -.

21. The pump-protecting armature according to one of claims 1 through 20, characterized in that a self-adjusting, spring-loaded friction damper (RD) formed from junk rings (47) is associated with the check-valve disk (7), and a hydraulic damper (HD) having a piston (43) of the throttling-body valve spindle (6) that extends into the second control bushing (42) screwed onto the control bushing (12), and is under spring tension (40), is associated with the throttle valve (9); and extending in the piston (43) and in the throttling bodies (11) is a connecting channel (51), which leads from the control bushing (42) and exits the control bushing (12) by way of a bore (52) that has a smaller cross section, with identical pressure ratios predominating in the space (53) between the piston (43) and the control bushing (42), and in the connecting channel (51) with the exit bore (52) (Fig. 2).